Connecting smaller bathroom sink drain to a large P-trap?

What would be the best way to connect sink drain? I got a straight pvc adapter that goes to the (2"?) drain in the wall, then to the P-trap, but then my sink's drain is almost 2x smaller than P-trap's opening. P-trap is 1-1/2" and sink's tailpiece is about 1-1/4 (or smaller)
Is there an adapter that I can readily get at HomeDepot or Lowes? What would it be called, because I couldn't find it